Re: [Intel-gfx] [PATCH v6 1/3] drm/i915/migrate: Account for the reserved_space

[Andi Shyti <andi.shyti@linux.intel.com>]

Hi Matt,

On Fri, Dec 02, 2022 at 12:28:42PM +0000, Matthew Auld wrote:
> From: Chris Wilson <chris.p.wilson@intel.com>
> 
> If the ring is nearly full when calling into emit_pte(), we might
> incorrectly trample the reserved_space when constructing the packet to
> emit the PTEs. This then triggers the GEM_BUG_ON(rq->reserved_space >
> ring->space) when later submitting the request, since the request itself
> doesn't have enough space left in the ring to emit things like
> workarounds, breadcrumbs etc.
> 
> v2: Fix the whitespace errors
> 
> Testcase: igt@i915_selftests@live_emit_pte_full_ring
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/7535
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6889
> Fixes: cf586021642d ("drm/i915/gt: Pipelined page migration")
> Signed-off-by: Chris Wilson <chris.p.wilson@intel.com>
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Cc: Andrzej Hajda <andrzej.hajda@intel.com>
> Cc: Andi Shyti <andi.shyti@linux.intel.com>
> Cc: Nirmoy Das <nirmoy.das@intel.com>
> Cc: <stable@vger.kernel.org> # v5.15+
> Tested-by: Nirmoy Das <nirmoy.das@intel.com>
> Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>

Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>

Thanks,
Andi